Back-pressure valve



Jan. 25, 1927. 1,615,81 1

L. M. PEARCE BACK PRES SURE VALVE Filed Nov. 5, 1923 Patented Jan. 25, 1927.

UNITED STATES AT i 1,615,811- ENT OFFICE.

LOUIS PEARCE, OF HOUSTON, TEXAS.

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Application filed November 5, 1928. Serial N9. 672,970.-

lower end of the screen. lln the preparation ot the well for production, a wash pipe is let down and its lower end rests on a suitable seat, provided for it, at the lower end of the screen, and water is forced down through this wash pipe beneath the screen, and the valve is arranged to open to permit this water to pass out of the lower end of the screen, and upon the outside of the screen to wash it so as to tree it from clogging matter to permit the tree inflow of oil through the screen, said valve closing to prevent the hack flow of fluid. lt is the object of this invention to providea novel combination of set sleeve, back pressure valve, and wash pipe seat.

It often happens that after the screen is set and washed, no oil is found, and the hole is often deepened, the work being carried on through the screen. In such cases, the wash ipe seat and valve must be removed from t e shoe, to give a. clear opening for the bit. The structure herein described is so designed that it can be easily removed by a suitable milling cutter, or other similar tool, and will drop down tothe bottom of the bore, and is there side tracked by the drilling tool and so disposed of.

Another object of the invention is to pro vide a device of the character described that is of very'simple construction, can be cheaply.

manulacturedand is very effective in use.

With the above and other objects in view, this invention has particular relation to certain novel features of construction, operation, and arrangement of parts, an example of which is'given in this specification, and illustrated in the accompanying drawings, wherein Figure 1 is a vertical sectional view of the device; and,

Fi re 2 is a cross sectional view taken on the hue 2-2 of Figure 1.

Referring now more particularly to the drawings, wherein like numerals of reference designate similar parts in each of the figures, the numeral 1 desi ates the screen pipe, and the numeral 2 esignates the set shoe which is threaded onto the lower end of the screen and which seats on the bottom of the bore when the screen is set. w 1

Within the set shoe there is a tubular casing 3 whose upper end is formed with an external, annular, outwardly threaded rib a which is screwed into the set shoe, and which anchors said casing therein. The casing also has an inwardl extending annular flange 5, at its upper en whose upper face converges downwardly, forming a seat 6 for the lower end of the wash pipe.

Within the casing, near its lower end, there'is a spider 7, having a central bearing 8.- There is a disc-like valve 9 whose upper surface is substantially convex, adapted to work against, and open or close the lower 7 end. of the casing 3. This valve has an upstanding stem 10 which works through the bearing 8 and whose upper end has a head ll. Surrounding this stem and interposed between the bearing 8 and head 11 there is a coil spring 12 which normally holds the valve in closed position. The casing 3 protects said spring and prevents slush and mud from packing around the same and so embedding it that it will not properly operate.

A. wash pipe (not shown) may be seated on the seat 6 and water forced downwardly through it will pass on down through the valve casing 3, and lift the valve and return to up around the screen and cleanse the same of clogging material. on the pressure through the wash pipeis cut 0d, the valve will automatically close to prevent the back flow of fluid up onto'the screen. as

If it be desired to deepen the bore,- the upper end of the casing 3 may be easily cut away by a suitable milling tool and the valve structure will drop to the bottom of the bore,

and will be easily side tracked in drilling 106 pletely closing the casing from beneath, yieldahle means within the casing and protected thereby normally holding the valve closedyall in combination with a wash pipe seat formed integrally with the upper end of the casing and in which the lower end of a wash pipe is adapted to fit and form a close fitting joint therewith so that the flushing fluid passing down through the wash pipe will pass ondown through the casing,

2. The combination with a set shoe of a tubular valve casing having an external annular outwardly threaded rib forming means for securing the casing-in and spacing it from the set shoe and whose upper end is outwardly flared forming a seat adapted to name.

receive the lower end of a wash and form a close fitting joint therewit the flushing fluid passing down through the wash pipe will" pass on down through the so that casing and protected thereby and normally holding the valve in closed position against the lower end of said casing and closing the casing from beneath.

In. testimony whereof I have signed my completely LOUIS M. PEARCE. 

